Power 864 PC5020 setup after factory reset issue

I verified that the installer code was not lock via the powering up and listening for clicking relay. I then reset the system to factory default. The default master code 1234 and default installer code 5555 or 5020 does not work nor do I have a ready light on. System goes blank if I type @8 5555 and gives a long beeb. When I hit #, it flashes through the eight zones. And help is appreciated. It\’s a premier pro.